Helleborus plant named ‘COSEH 3120’

ABSTRACT

A new and distinct cultivar of  Helleborus  plant named ‘COSEH 3120’, characterized by its relatively compact, upright and mounding plant habit; uniform and freely flowering habit; dark green-colored leaves; freely and early flowering habit; single white-colored flowers; and good garden performance.

Botanical designation: Helleborus niger.

Cultivar denomination: ‘COSEH 3120’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar ofHelleborus plant, botanically known as Helleborus niger and hereinafterreferred to by the name ‘COSEH 3120’.

The new Helleborus plant is a product of a planned breeding programconducted by the Inventor in Glandorf, Germany. The objective of thebreeding program was to create new uniform Helleborus plants with uniqueand attractive plant habit, leaf and flower coloration and resistance topests common to Helleborus plants.

The new Helleborus plant originated from a cross-pollination conductedby the Inventor in Glandorf, Germany in November, 2010 of two unnamedproprietary seedling selections of Helleborus niger, not patented. Thenew Helleborus plant was discovered and selected by the Inventor as asingle flowering plant from within the progeny of the statedcross-pollination grown in a controlled greenhouse environment inGlandorf, Germany in December, 2012.

Asexual reproduction of the new Helleborus plant by divisions in acontrolled environment in Glandorf, Germany since February, 2013 hasshown that the unique features of this new Helleborus plant are stableand reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Helleborus have not been observed under all possiblecombinations of environmental conditions and cultural practices. Thephenotype may vary somewhat with variations in environmental conditionssuch as temperature and light intensity without, however, any variancein genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘COSEH 3120’. These characteristics incombination distinguish ‘COSEH 3120’ as a new and distinct Helleborusplant:

-   -   1. Relatively compact, upright and mounding plant habit.    -   2. Uniform and freely flowering habit.    -   3. Dark green-colored leaves.    -   4. Freely and early flowering habit.    -   5. Single white-colored flowers.    -   6. Good garden performance.

Compared to plants of the parent selections, plants of the newHelleborus are more uniformly mounded and are more freely flowering.

Plants of the new Helleborus can be compared to plants of Helleborusniger ‘HGC Joshua’, disclosed in U.S. Plant Pat. No. 17,957. Inside-by-side comparisons, plants of the new Helleborus differ primarilyfrom plants of ‘HGC Joshua’ in the following characteristics:

-   -   1. Plants of the new Helleborus have larger flowers than plants        of ‘HGC Joshua’.    -   2. Plants of the new Helleborus flower later than plants of        plants of ‘HGC Joshua’.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new Helleborus plant showing the colors as true as it isreasonably possible to obtain in colored reproductions of this type.Colors in the photographs may differ slightly from the color valuescited in the detailed botanical description which accurately describethe colors of the new Helleborus plant.

The photograph on the first sheet is a side perspective view of atypical flowering plant of ‘COSEH 3120’ grown in a container.

The photograph on the second sheet is a close-up view of a typicalflower of ‘COSEH 3120’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations, measurementsand values describe plants grown during the autumn in 13-cm containersin a glass-covered greenhouse in Glandorf, Germany and under culturalpractices typical of commercial Helleborus production. During theproduction of the plants, day temperatures ranged from 12° C. to 32° C.and night temperatures ranged from 3° C. to 18° C. Plants were 14 monthsold when the photographs and the description were taken. In thefollowing description, color references are made to The RoyalHorticultural Society Colour Chart, 2015 Edition, except where generalterms of ordinary dictionary significance are used.

-   Botanical classification: Helleborus niger ‘COSEH 3120’.-   Parentage:    -   -   Female, or seed, parent.—Unnamed proprietary seedling            selection of Helleborus niger, not patented.        -   Male, or pollen, parent.—Unnamed proprietary seedling            selection of Helleborus niger, not patented.-   Propagation:    -   -   Type.—By tissue culture.        -   Time to initiate roots, winter.—About two months at            temperatures about 12° C.        -   Time to produce a rooted young plant, winter.—About six            months at temperatures ranging from 4° C. to 15° C.        -   Root description.—Thick to thin, fleshy; typically white to            brown in color, actual color of the roots is dependent on            substrate composition, water quality, fertilizer type and            formulation, substrate temperature and physiological age of            roots.        -   Rooting habit.—Sparse.-   Plant description:    -   -   Plant and growth habit.—Herbaceous perennial; relatively            compact, upright and mounding plant habit with flowers held            just above the foliar plane; plant shape, roughly flattened            globular; moderately vigorous growth habit; moderate growth            rate.        -   Plant height, soil level to top of foliar plane.—About 24.8            cm.        -   Plant height, soil level to top of flowers.—About 25.5 cm.        -   Plant diameter (area of spread).—About 34.5 cm.-   Leaf description:    -   -   Arrangement.—Leaves arranged in a basal rosette; leaves            palmately compound with typically seven leaflets per leaf.        -   Leaf length.—About 10.2 cm.        -   Leaf width.—About 12.1 cm.        -   Leaflet length.—About 9.2 cm.        -   Leaflet width.—About 3.5 cm.        -   Leaf shape.—Palmate; reniform in outline.        -   Leaflet shape.—Narrowly obovate.        -   Leaflet apex.—Abruptly acute.        -   Leaflet base.—Attenuate.        -   Leaflet margin.—Serrate; revolute.        -   Leaflet texture and luster, upper surface.—Smooth, glabrous;            slightly rugose; slightly glossy.        -   Leaflet texture and luster, lower surface.—Smooth, glabrous;            slightly rugose; matte.        -   Leaflet venation pattern.—Pinnate.        -   Leaflet color.—Developing leaflets, upper surface: Close to            137A. Developing leaflets, lower surface: Close to 147B.            Fully developed leaflets, upper surface: Close to darker            than between 139A and 147A; venation, close to 147B. Fully            developed leaflets, lower surface: Close to 143A; venation,            close to 144A.        -   Petioles.—Length: About 14.2 cm. Diameter: About. 6.5 mm.            Strength: Strong. Texture and luster, upper and lower            surfaces: Smooth, glabrous; slightly glossy. Color, upper            and lower surfaces: Close to 144A to 144B, slightly to            heavily tinged and speckled with close to 178A to 178B.-   Flower description:    -   -   Flower shape and habit.—Single rotate flowers arranged            solitary or in pairs; freely and uniform flowering habit            with about 36 flowers developing per plant; flowers facing            slightly upright, outwardly to slightly nodding.        -   Fragrance.—None detected.        -   Natural flowering season.—Plants begin flowering about ten            months after planting; plants flower from autumn into winter            in Germany.        -   Flower longevity on the plant.—About ten days; flowers not            persistent.        -   Flower buds.—Length: About 2.3 cm. Diameter: About 1.1 cm.            Shape: Ovate. Texture and luster: Glabrous; slightly glossy.            Color: Close to 157A; towards the base, close to 145C and            145D.        -   Flower diameter.—About 8.2 cm.        -   Flower depth (height).—About 3.3 cm.        -   Petals.—Transformed into nectaries.        -   Sepals.—Quantity and arrangement: About five to eight,            arranged in a single whorl. Length: About 4.2 cm. Width:            About 3.3 cm. Shape: Broadly ovate. Apex: Obtuse. Base:            Cuneate. Margin: Entire. Texture and luster, upper surface:            Glabrous; matte. Texture and luster, lower surface:            Glabrous; slightly glossy. Color: When opening, upper            surface: Close to NN155C. When opening, lower surface: Close            to NN155B; occasionally towards the base, slightly tinged            with close to 186D. Fully opened, upper surface: Close to            NN155B to NN155C. Fully opened, lower surface: Close to            NN155B; occasionally towards the base, slightly tinged with            close to 186C to 186D.        -   Flower bracts.—Quantity per flower: Typically one. Length:            About 4.3 cm. Width: About 2.3 cm. Shape: Ovate. Apex:            Acute. Base: Broadly cuneate. Margin: Entire; undulate.            Color, upper surface: Close to 137A to 137C; venation, close            to 144B. Color, lower surface: Close to 144A; venation,            close to 183B.        -   Peduncles.—Length: About 22.6 cm. Diameter: About 6 mm.            Aspect: About 15° from vertical. Strength: Moderately            strong. Texture and luster: Glabrous; moderately glossy.            Color: Close to 145B to 145C, speckled with close to 178B.        -   Pedicels.—Length: About 6.3 cm. Diameter: About 4 mm.            Aspect: About 30° from peduncle axis. Strength: Moderately            strong. Texture and luster: Glabrous; moderately glossy.            Color: Close to 145B to 145C, speckled with close to 178B.        -   Reproductive organs.—Stamens: Quantity per flower:            About 150. Filament length: About 1.3 cm. Filament color:            Close to NN155D. Anther shape: Reniform; basifixed. Anther            size: About 1.75 mm by 2 mm. Anther color: Close to 3C.            Pollen amount: Moderate. Pollen color: Close to 2D. Pistils:            Quantity per flower: About 8 to 13. Pistil length: About            1 cm. Stigma diameter: About 0.3 mm. Stigma shape:            Club-shaped. Stigma color: Close to NN155A. Style length:            About 9.5 mm. Style color: Close to NN155C. Ovary color:            Close to lighter than 150D. Nectaries (transformed petals):            Quantity per flower: About 18. Length: About 1 cm. Diameter:            About 2.5 mm. Shape: Tubular, flattened. Texture and luster,            inner surface: Smooth, glabrous; matte. Texture and luster,            outer surface: Smooth, glabrous; glossy. Color, immature,            inner and outer surfaces: Close to 150B; towards the apex,            close to 150C. Color, mature, inner and outer surfaces:            Close to 150A; towards the apex, close to 9B.        -   Seeds and fruits.—Seed and fruit development have not been            observed on plants of the new Helleborus.-   Garden performance: Plants of the new Helleborus have been observed    to have good garden performance and to tolerate rain, wind and to be    suitable for USDA Hardiness Zones 5 through 9.-   Pathogen & pest resistance: Plants of the new Helleborus have not    been observed to be resistant to pathogens and pests common to    Helleborus plants.

It is claimed:
 1. A new and distinct Helleborus plant named ‘COSEH 3120’as illustrated and described.